You are a shipyard and have performed expensive repairs on a fishing
boat or yacht. The owner isn’t too happy about the bill and may even
dispute some of it, and he’s threatening to sue if you don’t give him
the boat.

A maritime lien gives a provider of fuel, repair services etc. an automatic lien on the ship to which the the services were provided. The lien allows the provider to seize the ship and sell it in satisfaction of the lien and the costs of sale.

Salvage Claims & Awards Under Admiralty Law. I
am tending traps in my lobster boat one blustery fall day, and as I
watch an expensive yacht run up on a ledge. The yacht backs away from
the ledge, then loses power...